Stereotactic Radiosurgery for Brain Lesions: An Observation and Follow-up

Abstract OBJECTIVE: Despite the success of stereotactic radiosurgery, large inoperable arteriovenous malformations (AVMs) of 14 cm3 or more have remained largely refractory to stereotactic radiosurgery, with much lower obliteration rates. We review treatment of large AVMs either previously untreated or partially obliterated by embolization with fractionated stereotactic radiotherapy (FSR) regimens using a dedicated linear accelerator (LINAC). METHODS: Before treatment, all patients were discussed at a multidisciplinary radiosurgery board and found to be suitable for FSR. All patients were evaluated for pre-embolization. Those who had feeding pedicles amenable to glue embolization were treated. LINAC technique involved acquisition of a stereotactic angiogram in a relocatable frame that was also used for head localization during treatment. The FSR technique involved the use of six 7-Gy fractions delivered on alternate days over a 2-week period, and this was subsequently dropped to 5-Gy fractions after late complications in one of seven patients treated with 7-Gy fractions. Treatments were based exclusively on digitized biplanar stereotactic angiographic data. We used a Varian 600SR LINAC (Varian Medical Systems, Inc., Palo Alto, CA) and XKnife treatment planning software (Radionics, Inc., Burlington, MA). In most cases, one isocenter was used, and conformality was established by non-coplanar arc beam shaping and differential beam weighting. RESULTS: Thirty patients with large AVMs were treated between January 1995 and August 1998. Seven patients were treated with 42-Gy/7-Gy fractions, with one patient lost to follow-up and the remaining six with previous partial embolization. Twenty-three patients were treated with 30-Gy/5-Gy fractions, with two patients lost to follow-up and three who died as a result of unrelated causes. Of 18 evaluable patients, 8 had previous partial embolization. Mean AVM volumes at FSR treatment were 23.8 and 14.5 cm3, respectively, for the 42-Gy/7-Gy fraction and 30-Gy/5-Gy fraction groups. After embolization, 18 patients still had AVM niduses of 14 cm3 or more: 6 in the 7-Gy cohort and 12 in the 5-Gy cohort. For patients with at least 5-year follow-up, angiographically documented AVM obliteration rates were 83% for the 42-Gy/7-Gy fraction group, with a mean latency of 108 weeks (5 of 6 evaluable patients), and 22% for the 30-Gy/5-Gy fraction group, with an average latency of 191 weeks (4 of 18 evaluable patients) (P = 0.018). For AVMs that remained at 14 cm3 or more after embolization (5 of 6 patients), the obliteration rate remained 80% (4 of 5 patients) for the 7-Gy cohort and dropped to 9% for the 5-Gy cohort. A cumulative hazard plot revealed a 7.2-fold greater likelihood of obliteration with the 42-Gy/7-Gy fraction protocol (P = 0.0001), which increased to a 17-fold greater likelihood for postembolization AVMs of 14 cm3 or more (P = 0.003). CONCLUSION: FSR achieves obliteration for AVMs at a threshold dose, including large residual niduses after embolization. With significant treatment-related morbidities, further investigation warrants a need for better three-dimensional target definition with higher dose conformality.

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Biologically effective dose correlates with linear tumor volume changes after upfront single-fraction stereotactic radiosurgery for vestibular schwannomas

Neurosurgical Review ◽

10.1007/s10143-021-01538-w ◽

2021 ◽

Author(s):

Constantin Tuleasca ◽

Mohamed Faouzi ◽

Philippe Maeder ◽

Raphael Maire ◽

Jonathan Knisely ◽

...

Keyword(s):

Standard Deviation ◽

Effective Dose ◽

Stereotactic Radiosurgery ◽

Tumor Volume ◽

Vestibular Schwannomas ◽

Benign Tumors ◽

Biologically Effective Dose ◽

Volume Changes ◽

Single Fraction

AbstractVestibular schwannomas (VSs) are benign, slow-growing tumors. Management options include observation, surgery, and radiation. In this retrospective trial, we aimed at evaluating whether biologically effective dose (BED) plays a role in tumor volume changes after single-fraction first intention stereotactic radiosurgery (SRS) for VS. We compiled a single-institution experience (n = 159, Lausanne University Hospital, Switzerland). The indication for SRS was decided after multidisciplinary discussion. Only cases with minimum 3 years follow-up were included. The Koos grading, a reliable method for tumor classification was used. Radiosurgery was performed using Gamma Knife (GK) and a uniform marginal prescription dose of 12 Gy. Mean BED was 66.3 Gy (standard deviation 3.8, range 54.1–73.9). The mean follow-up period was 5.1 years (standard deviation 1.7, range 3–9.2). The primary outcome was changes in 3D volumes after SRS as function of BED and of integral dose received by the VS. Random-effect linear regression model showed that tumor volume significantly and linearly decreased over time with higher BED (p < 0.0001). Changes in tumor volume were also significantly associated with age, sex, number of isocenters, gradient index, and Koos grade. However, the effect of BED on tumor volume change was moderated by time after SRS and Koos grade. Lower integral doses received by the VSs were inversely correlated with BED in relationship with tumor volume changes (p < 0.0001). Six (3.4%) patients needed further intervention. For patients having uniformly received the same marginal dose prescription, higher BED linearly and significantly correlated with tumor volume changes after SRS for VSs. BED could represent a potential new treatment paradigm for patients with benign tumors, such as VSs, for attaining a desired radiobiological effect. This could further increase the efficacy and decrease the toxicity of SRS not only in benign tumors but also in other SRS indications.

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Stereotactic radiosurgery for treating meningiomas eligible for complete resection

Radiation Oncology ◽

10.1186/s13014-021-01748-y ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Maximilian I. Ruge ◽

Juman Tutunji ◽

Daniel Rueß ◽

Eren Celik ◽

Christian Baues ◽

...

Keyword(s):

Adverse Events ◽

Stereotactic Radiosurgery ◽

Medical Condition ◽

Local Tumor Control ◽

Complete Resection ◽

Neurological Deficits ◽

Tumor Control ◽

Recurrence Rates ◽

Treatment Volume

Abstract Background For meningiomas, complete resection is recommended as first-line treatment while stereotactic radiosurgery (SRS) is established for meningiomas of smaller size considered inoperable. If the patient´s medical condition or preference excludes surgery, SRS remains a treatment option. We evaluated the efficacy and safety of SRS in a cohort comprising these cases. Methods In this retrospective single-centre analysis we included patients receiving single fraction SRS either by modified LINAC or robotic guidance by Cyberknife for potentially resectable intracranial meningiomas. Treatment-related adverse events as well as local and regional control rates were determined from follow-up imaging and estimated by the Kaplan–Meier method. Results We analyzed 188 patients with 218 meningiomas. The median radiological, and clinical follow-up periods were 51.4 (6.2–289.6) and 55.8 (6.2–300.9) months. The median tumor volume was 4.2 ml (0.1–22), and the mean marginal radiation dose was 13.0 ± 3.1 Gy, with reference to the 80.0 ± 11.2% isodose level. Local recurrence was observed in one case (0.5%) after 239 months. The estimated 2-, 5-, 10- and 15-year regional recurrence rates were 1.5%, 3.0%, 6.6% and 6.6%, respectively. Early adverse events (≤ 6 months after SRS) occurred in 11.2% (CTCEA grade 1–2) and resolved during follow-up in 7.4% of patients, while late adverse events were documented in 14.4% (grade 1–2; one case grade 3). Adverse effects (early and late) were associated with the presence of symptoms or neurological deficits prior to SRS (p < 0.03) and correlated with the treatment volume (p < 0.02). Conclusion In this analysis SRS appears to be an effective treatment for patients with meningiomas eligible for complete resection and provides reliable long-term local tumor control with low rates of mild morbidity.

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Tufts Medical Center Experience with Long Term Follow up of Vestibular Schwannoma Treated with Gamma Knife Stereotactic Radiosurgery: Novel Finding of Delayed Pseudoprogression

Advances in Radiation Oncology ◽

10.1016/j.adro.2021.100687 ◽

2021 ◽

pp. 100687

Author(s):

Justin Wage ◽

John Mignano ◽

Julian Wu

Keyword(s):

Stereotactic Radiosurgery ◽

Gamma Knife ◽

Vestibular Schwannoma ◽

Medical Center ◽

Long Term Follow Up ◽

Gamma Knife Stereotactic Radiosurgery

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Stereotactic radiosurgery at a low marginal dose for the treatment of pediatric arteriovenous malformations: obliteration, complications, and functional outcomes

Journal of Neurosurgery Pediatrics ◽

10.3171/2014.3.peds13381 ◽

2014 ◽

Vol 14 (1) ◽

pp. 1-11 ◽

Cited By ~ 33

Author(s):

Matthew B. Potts ◽

Sunil A. Sheth ◽

Jonathan Louie ◽

Matthew D. Smyth ◽

Penny K. Sneed ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Functional Outcomes ◽

Arteriovenous Malformations ◽

Target Volume ◽

Neurological Deficits ◽

Single Institution ◽

Risks And Benefits ◽

Scale Scores ◽

Time Of Presentation

Object Stereotactic radiosurgery (SRS) is an established treatment modality for brain arteriovenous malformations (AVMs) in children, but the optimal treatment parameters and associated treatment-related complications are not fully understood. The authors present their single-institution experience of using SRS, at a relatively low marginal dose, to treat AVMs in children for nearly 20 years; they report angiographic outcomes, posttreatment hemorrhage rates, adverse treatment-related events, and functional outcomes. Methods The authors conducted a retrospective review of 2 cohorts of children (18 years of age or younger) with AVMs treated from 1991 to 1998 and from 2000 to 2010. Results A total of 80 patients with follow-up data after SRS were identified. Mean age at SRS was 12.7 years, and 56% of patients had hemorrhage at the time of presentation. Median target volume was 3.1 cm3 (range 0.09–62.3 cm3), and median prescription marginal dose used was 17.5 Gy (range 12–20 Gy). Angiograms acquired 3 years after treatment were available for 47% of patients; AVM obliteration was achieved in 52% of patients who received a dose of 18–20 Gy and in 16% who received less than 18 Gy. At 5 years after SRS, the cumulative incidence of hemorrhage was 25% (95% CI 16%–37%). No permanent neurological deficits occurred in patients who did not experience posttreatment hemorrhage. Overall, good functional outcomes (modified Rankin Scale Scores 0–2) were observed for 78% of patients; for 66% of patients, functional status improved or remained the same as before treatment. Conclusions A low marginal dose minimizes SRS-related neurological deficits but leads to low rates of obliteration and high rates of hemorrhage. To maximize AVM obliteration and minimize posttreatment hemorrhage, the authors recommend a prescription marginal dose of 18 Gy or more. In addition, SRS-related symptoms such as headache and seizures should be considered when discussing risks and benefits of SRS for treating AVMs in children.

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Radiosurgery for Treatment of Recurrent Intracranial Hemangiopericytomas

Neurosurgery ◽

10.1097/00006123-200210000-00008 ◽

2002 ◽

Vol 51 (4) ◽

pp. 905-911 ◽

Cited By ~ 19

Author(s):

Jason Sheehan ◽

Douglas Kondziolka ◽

John Flickinger ◽

L. Dade Lunsford

Keyword(s):

Stereotactic Radiosurgery ◽

Survival Rates ◽

Gamma Knife Radiosurgery ◽

Residual Tumor ◽

Local Tumor Control ◽

Tumor Control ◽

Local Tumor ◽

University Of Pittsburgh ◽

Kaplan Meier

Abstract OBJECTIVE Hemangiopericytomas are highly aggressive meningeal tumors with tendencies for recurrence and metastasis. The purpose of this retrospective, single-institution review was to evaluate the efficacy and role of stereotactic radiosurgery in the management of recurrent hemangiopericytomas. METHODS We reviewed data for patients who underwent stereotactic radiosurgery at the University of Pittsburgh between 1987 and 2001. Fourteen patients underwent radiosurgery for 15 discrete tumors. Prior treatments included transsphenoidal resection (n = 1), craniotomy and resection (n = 27), embolization (n = 1), and conventional radiotherapy (n = 7). Clinical and radiological responses were evaluated. Follow-up periods varied from 5 to 76 months (mean, 31.3 mo; median, 21 mo). The mean radiation dose to the tumor margin was 15 Gy. RESULTS Seventy-nine percent of patients (11 of 14 patients) with recurrent hemangiopericytomas demonstrated local tumor control after radiosurgery. Twelve of 15 tumors (i.e., 80%) dramatically decreased in size on follow-up imaging scans. Regional intracranial recurrences were retreated with radiosurgery for two patients (i.e., 15%); neither of those two patients experienced long-term tumor control. Local recurrences occurred 12 to 75 months (median, 21 mo) after radiosurgery. Local tumor control and survival rates at 5 years after radiosurgery were 76 and 100%, respectively (Kaplan-Meier method). We could not correlate prior irradiation or tumor size with tumor control. Twenty-nine percent of the patients (4 of 14 patients) developed remote metastases. Radiosurgery did not seem to offer protection against the development of intra- or extracranial metastases. CONCLUSION Gamma knife radiosurgery provided local tumor control for 80% of recurrent hemangiopericytomas. When residual tumor is identified after resection or radiotherapy, early radiosurgery should be considered as a feasible treatment modality. Despite local tumor control, patients are still at risk for distant metastasis. Diligent clinical and radiological follow-up monitoring is necessary.

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TREATMENT OF SPINAL TUMORS USING CYBERKNIFE FRACTIONATED STEREOTACTIC RADIOSURGERY

Neurosurgery ◽

10.1227/01.neu.0000338072.30246.bd ◽

2009 ◽

Vol 64 (2) ◽

pp. 297-307 ◽

Cited By ~ 79

Author(s):

Gregory J. Gagnon ◽

Nadim M. Nasr ◽

Jay J. Liao ◽

Inge Molzahn ◽

David Marsh ◽

...

Keyword(s):

Quality Of Life ◽

Stereotactic Radiosurgery ◽

University Hospital ◽

Postoperative Treatment ◽

Spinal Tumors ◽

Radiation Toxicity ◽

Pain Scores ◽

Component Scores

Abstract OBJECTIVE Benign and malignant tumors of the spine significantly impair the function and quality of life of many patients. Standard treatment options, including conventional radiotherapy and surgery, are often limited by anatomic constraints and previous treatment. Image-guided stereotactic radiosurgery using the CyberKnife system (Accuray, Inc., Sunnyvale, CA) is a novel approach in the multidisciplinary management of spinal tumors. The aim of this study was to evaluate the effects of CyberKnife stereotactic radiosurgery on pain and quality-of-life outcomes of patients with spinal tumors. METHODS We conducted a prospective study of 200 patients with benign or malignant spinal tumors treated at Georgetown University Hospital between March 2002 and September 2006. Patients were treated by means of multisession stereotactic radiosurgery using the CyberKnife as initial treatment, postoperative treatment, or retreatment. Pain scores were assessed by the Visual Analog Scale, quality of life was assessed by the SF-12 survey, and neurological examinations were conducted after treatment. RESULTS Mean pain scores decreased significantly from 40.1 to 28.6 after treatment (P < 0.001) and continued to decrease over the entire 4-year follow-up period (P < 0.05). SF-12 Physical Component scores demonstrated no significant change throughout the follow-up period. Mental Component scores were significantly higher after treatment (P < 0.01), representing a quality-of-life improvement. Early side effects of radiosurgery were mild and self-limited, and no late radiation toxicity was observed. CONCLUSION CyberKnife stereotactic radiosurgery is a safe and effective modality in the treatment of patients with spinal tumors. CyberKnife offers durable pain relief and maintenance of quality of life with a very favorable side effect profile.

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STEREOTACTIC RADIOSURGERY FOR CAVERNOUS SINUS OR ORBITAL HEMANGIOMAS

Neurosurgery ◽

10.1227/01.neu.0000356987.98197.71 ◽

2009 ◽

Vol 65 (5) ◽

pp. 914-918 ◽

Cited By ~ 28

Author(s):

Aftab A. Khan ◽

Ajay Niranjan ◽

Hideyuki Kano ◽

Douglas Kondziolka ◽

John C. Flickinger ◽

...

Keyword(s):

Stereotactic Radiosurgery ◽

Cavernous Sinus ◽

Tumor Regression ◽

Target Volume ◽

Symptomatic Improvement ◽

Primary Treatment ◽

Vascular Tumors ◽

Presenting Symptoms ◽

Primary Treatment Modality

Abstract OBJECTIVE Hemangiomas are rare but highly vascular tumors that may develop in the cavernous sinus or orbit. These tumors pose diagnostic as well as therapeutic challenges to neurosurgeons during attempted removal. We analyzed our increasing experience using stereotactic radiosurgery (SRS). METHODS Eight symptomatic patients with hemangiomas underwent SRS between 1988 and 2007. The presenting symptoms included headache, orbital pain, diplopia, ptosis, proptosis and impaired visual acuity. The hemangiomas were located in either the cavernous sinus (7 patients) or the orbit (1 patient). Four patients underwent SRS as primary treatment modality based on clinical and imaging criteria. Four patients had previous microsurgical partial excision or biopsy. The median target volume was 6.8 mL (range, 2.5–18 mL). The median prescription dose delivered to the margin was 14.5 Gy (range, 12.5–19 Gy). The dose to the optic nerve in all patients was less than 9 Gy (range, 4.5–9 Gy). RESULTS The median follow-up period after SRS was 80 months (range, 40–127 months). Six patients had symptomatic improvement; 2 patients reported persistent diplopia. Follow-up imaging revealed tumor regression in 7 patients and no change in tumor volume in 1 patient. All the patients improved after SRS. CONCLUSION Our extended experience confirms that SRS is an effective management strategy for symptomatic intracavernous and intraorbital hemangiomas. Our study is the first long-term report on the safety and efficacy of SRS.

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Preliminary results of linear accelerator radiosurgery for acoustic schwannomas

Journal of Neurosurgery ◽

10.3171/jns.1996.85.6.1013 ◽

1996 ◽

Vol 85 (6) ◽

pp. 1013-1019 ◽

Cited By ~ 79

Author(s):

William M. Mendenhall ◽

William A. Friedman ◽

John M. Buatti ◽

Francis J. Bova

Keyword(s):

Stereotactic Radiosurgery ◽

Local Control ◽

Linear Accelerator ◽

Local Control Rate ◽

Magnetic Resonance Images ◽

High Rate ◽

Content Type ◽

Treatment Volume ◽

Fine Print

✓ In this paper the authors evaluate the results of linear accelerator (LINAC)—based stereotactic radiosurgery for acoustic schwannomas. Fifty-six patients underwent LINAC-based stereotactic radiosurgery for acoustic schwannomas at the University of Florida between July 1988 and November 1994. Each patient was followed for a minimum of 1 year or until death; no patient was lost to follow up. One or more follow-up magnetic resonance images or computerized tomography scans were obtained in 52 of the 56 patients. Doses ranged between 10 and 22.5 Gy with 69.6% of patients receiving 12.5 to 15 Gy. Thirty-eight patients (68%) were treated with one isocenter and the dose was specified to the 80% isodose line in 71% of patients. Fifty-five patients (98%) achieved local control after treatment. The 5-year actuarial local control rate was 95%. At the time of analysis, 48 patients were alive and free of disease, seven had died of intercurrent disease, and one was alive with disease. Complications developed in 13 patients (23%). The likelihood of complications was related to the dose and treatment volume: 10 to 12.5 Gy to all volumes, three (13%) of 23 patients; 15 to 17.5 Gy to 5.5 cm3 or less, two (9%) of 23 patients; 15 to 17.5 Gy to more than 5.5 cm3, five (71%) of seven patients; and 20 to 22.5 Gy to all volumes, three (100%) of three patients. Linear accelerator—based stereotactic radiosurgery results in a high rate of local control at 5 years. The risk of complications is related to the dose and treatment volume.

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Dose—response tolerance of the visual pathways and cranial nerves of the cavernous sinus to stereotactic radiosurgery

Journal of Neurosurgery ◽

10.3171/jns.1998.88.1.0043 ◽

1998 ◽

Vol 88 (1) ◽

pp. 43-50 ◽

Cited By ~ 367

Author(s):

Klaus A. Leber ◽

Jutta Berglöff ◽

Gerhard Pendl

Keyword(s):

Stereotactic Radiosurgery ◽

Cavernous Sinus ◽

Dose Response ◽

Cranial Nerves ◽

Visual Pathways ◽

Content Type ◽

Number Of Patients ◽

Response Tolerance ◽

Fine Print

As the number of patients treated with stereotactic radiosurgery increases, it becomes particularly important to define with precision adverse effects on distinct structures of the nervous system. Object. This study was designed to assess the dose—response tolerance of the visual pathways and cranial nerves after exposure of the cavernous sinus to radiation. Methods. A total of 66 sites in the visual system and 210 cranial nerves of the middle cranial fossa were investigated in 50 patients who had undergone gamma knife treatment for benign skull base tumors. The mean follow-up period was 40 months (range 24–60 months). Follow-up examinations consisted of neurological, neuroradiological, and neuroophthalmological evaluations. The actuarial incidence of optic neuropathy was zero for patients who received a radiation dose of less than 10 Gy, 26.7% for patients receiving a dose in the range of 10 to less than 15 Gy, and 77.8% for those who received doses of 15 Gy or more (p < 0.0001). Previously impaired vision improved in 25.8% and was unchanged in 51.5% of patients. No sign of neuropathy was seen in patients whose cranial nerves of the cavernous sinus received radiation doses of between 5 and 30 Gy. Because tumor control appeared to have been achieved in 98% of the patients, the deterioration in visual function cannot be attributed to tumor progression. Conclusions. The structures of the visual pathways (the optic nerve, chiasm, and tract) exhibit a much higher sensitivity to single-fraction radiation than other cranial nerves, and their particular dose—response characteristics can be defined. In contrast, the oculomotor and trigeminal nerves have a much higher dose tolerance.

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